• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1055-1059
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• 2006

가입자망의 구현 형태의 하나인 EPON(Ethernet Passive Optical Network)에서의 대역할당 방식을 다룬다. EPON의 서비스 성능은 상향 트래픽을 어떻게 처리해주는 가에 영향을 많이 받는데, 본 논문에서는 4가지 등급으로 구분된 서비스 트래픽에 대한 QoS(Quality of Service)를 고려한 데이터 전송 서비스를 위한 알고리즘을 하나 제시하고, 이에 대한 성능 분석을 위해 시뮬레이션을 한다.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.65-74
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• 2003

In this Paper, we propose a downlink service admission strategy that considers users QoS requirements by using a novel service quality prediction index for multi-service WCDMA mobile systems. The Proposed downlink service admission strategy is obtained by computing average received Power of each service, assuming a relative other-cell interference factor. With the proposed method we obtain a downlink service admission region where users of different services properly can be admitted. And adding the fairness at the proposed downiinh service admission strategy, we Propose another downlink service admission strategy. In the numerical examples, the downlink service admission region with fairness and the downlink service admission region without fairness of voice service and data services are obtained by proposed downlink service admission strategies, respectively.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.161-169
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• 2009

The development of Wireless Multimedia Sensor Networks(WMSNs) is getting realized in accordance with the increased demands to provide multimedia data transmission service such as CCTV movie, image chapter information, audio information based on wireless sensor network. It is very important to provide the differentiated quality assurance of service. In this paper, we propose a sensor medium access control protocol based on DSMAC, which provides differentiated Quality of Service(QoS) for delay. A proposed protocol is able to reduce the delay without increasing the energy consumption by adaptively changing the duty cycle according to the buffer occupancy. Simulation results show that the new MAC protocol performs better in terms of latency than S-MAC and DSMAC.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.764-773
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• 2011

IEEE 802.15.4 is a standard for LWPAN based on TDMA. IEEE 802.15.4 has not been used widely because of restrictions on the QoS, scalability, and reliability. IEEE 802.15.4 utilizes GTS for one-hop QoS transmission. However GTS is not an effective method to satisfy QoS in multi-hop environments. Currently IEEE 802.15.4e, an extended version of IEEE 802.15.4 MAC sub-layer, is being developed to satisfy more diverse performance requirements than IEEE 802.15.4. IEEE 802.15.4e provides muti-hop QoS transmission functionality and uses multiple frequency channels. In this paper, a multi-channel TDMA scheduling scheme is proposed to satisfy end-to-end transmission delay in IEEE 802.15.4e. The performance of the proposed scheme is evaluated using simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.7
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• pp.30-37
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• 2002

In this paper, we propose a new adaptive slot assignment algorithm called In-VDSA in order to guarantee the QoS(Quality of Service) of VBR(Variable Bit Rate) traffics in wireless ATM and maximize efficiency in use of wireless channels. In the proposed algorithm, the status of terminal buffers is encoded in signed number on the GFC(Generic Flow Control) field of an ATM cell header and piggybacked. And also, the number of slots to be assigned to the next frame is adjusted effectively, which is different to methods in the conventional slot assignment algorithms. As a result, we can guarantee QoS such as CLR(Cell Loss Rate) and cell delay and achieve the higher utilization of channels. The validity of the proposed algorithm has been justified in performance by analysis through simulation results using the BONeS tool and comparison with conventional methods.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1811-1818
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• 2013

As the broadband network are being deployed recently, the IPTV (Internet Protocol TV) has appeared and become a most representative service that incorporates audio, video, etc. In spite of the long-period efforts, however, no standardized method exists to measure and evaluate the quality of video that is experienced through TV in the customer's premises. Therefore, before developing a method to measure and evaluate the quality of experience (QoE) for video that is the ultimate goal, this paper reviews the outcomes from the past standardization activities and drive a few important implications that would be reflected to the method to measure and evaluate QoE for video.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.467-476
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• 2003

In this paper, we propose an efficient MAC scheduling algorithm for supporting Bluetooth scatternet operations. Our proposed algorithm improves overall performances of scatter mode［2, 3] and considers QoS requirements of each link of the bridge node of a scatternet. Scatter mode is based on time division scheduling and provides every links of a scatternet with fair service opportunities. However, since each Bluetooth devices has various traffic characteristics. fair allocation of service opportunities is not efficient and may cause extravagance of wireless resources. Therefore, we propose a new efficient inter-piconet scheduling algorithm compliant with the current Bluetooth specification［1］, and demonstrate its improved performances via computer simulations.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.441-447
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• 2003

Recently there is a growing Interest In mobile cellula r network providing multimedia service. However, the link bandwidth of mobile cellular network is not sufficient enough to provide satisfactory services to use rs. To overcome this problem, an adaptive framework has been proposed in this study, we propose a new method of estimating DPR(degradation period ratio) in an adaptive multimedia network where the bandwidth of ongoing call can be dynamically adjusted during its lifetime. DPR is a QoS(quality of service) parameter which represents the ratio of allocated bandwidth below a pre-defined target to the whole service time of a call. We improve estimation method of DPR using DTMC(discrete time Markov chain) model. We also calculate mean degradation period and degradation probability more precisely than in existing studies. Under Threshold CAC(call admission control) algorithm, we present analytically how to guarantee QoS to users and illustrate the method by numerical examples. The proposed method is expected to be used as one of CAC schemes in guaranteeing predefined QoS level of DPR

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.653-657
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• 2003

Mobile Number Portability means a network capability that users can change service provider while retaining a legacy mobile phone number. Therefore, n provides users with convenience to select service provider comparing service's quality and rate without changing a phone number. in our country, 2G MNP service of QoR method is going to serve in January, 2004. In this paper, We describe connection protocol and NMP procedure between SSP and SCP in order to provide 2G MNP service in domestic network

• Journal of Korea Multimedia Society
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• v.11 no.5
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• pp.673-684
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• 2008

In this paper, we propose a signaling protocol which can support QoS for multimedia applications continuously after handover of a mobile node in the network environment where IP-based wireless access networks co-exist. Since existing RSVP-based signaling protocols can cause the waste of network resources due to double reservation and do not provide fast resource reservation/release, they are not suitable for mobile networks. The proposed QoS signaling protocol can support QoS for multimedia applications using the fast reservation of necessary resources after handover and avoid the waste of resources by resolving the double reservation problem. This paper presents design and implementation architectures of the proposed signaling protocol and analyzes its performance via a physical testbed. Based on the analysis results, it was shown that the proposed protocol is able to support seamless QoS for multimedia applications.